June 11, 2012: On June 1st the latest nuclear-powered Virginia class attack submarine, the USS Mississippi (SSN-782), entered service. Costing over $2 billion, the 7,800-ton boat has a length of 114.9 meters (377 feet) and is of 10.36 meters (34 feet) wide. Top speed is over 50 kilometers an hour and the boat can dive beyond 243.84 meters (800 feet).

As an attack submarine, the USS Mississippi is designed for both conventional and unconventional operational roles. In the traditional sense, the sub can conduct standard anti-surface and anti-submarine operations with its Tomahawk land attack missiles (12 vertical launching tubes) and advanced MK-48 torpedoes (four 53.3 centimeter, 21-inch torpedo tubes) as well as deployable mobile mines.

The new sub, though, is also capable of managing operations that most predecessors were not capable of. Of particular significance is the sub’s unequaled and singular operational capacity to operate as a submersed stealth craft, being an extremely difficult to detect maritime-base for direct intelligence collection operations. The USS Mississippi is outfitted with countermining acoustic capabilities to limit detection signatures, automated torpedo recognition systems, and the latest electronic warfare systems, backed by enhanced data processing and control systems. In sum, the new sub has been outfitted with a tremendous amount of cutting-edge intelligence, surveillance, and reconnaissance gear to better support conventional, asymmetric, and irregular warfare operations globally.

The USS Mississippi can operate in extremely shallow waters to support special operation forces – conveying and deploying the SEAL Delivery Vehicle as well as the ability to dispatch manned divers from the sub itself. The Mississippi’s ability to operate in so-called “brown waters” or low lying, unfriendly coastal areas and its purposed design to support unmanned underwater vehicles, enables it to be an effective clandestine platform for specialized operations, particularly for low-intensity conflicts or to conduct highly sensitive, low footprint mission profiles.

The Virginia reactors are designed to be fueled once, with a 33 year supply of fuel that can generate up to 40,000 horsepower for propulsion or electricity for the crew of 132. The Mississippi is ninth of ten "Block II" Virginias. The only difference with the four Block II is some less costly construction techniques. There are also to be eight Block III boats, with some design changes and new technology.

The U.S. currently has three classes of SSN. Most are the 6,900 ton Los Angeles-class SSNs. Sixty-two of these submarines were built, and 41 are still in service. Armed with four 21-inch (533-millimeter) torpedo tubes, they carry twenty-six weapons for those tubes (either the Mk 48 torpedoes or BGM-109 Tomahawk cruise missiles). The last 31 Los Angeles-class SSNs added the Mk 45 vertical-launch system (VLS), which carries another twelve Tomahawks. If built today these late model Los Angeles class boats would cost about $1.5 billion each.

The twenty-nine 9,000 ton Seawolf-class SSNs were supposed to replace the Los Angeles boats but Seawolf proved too expensive. Only three were built. The Seawolf was designed for the Cold War, carrying fifty weapons (torpedoes, cruise missiles, or Harpoon anti-ship missiles) for its eight 26-inch (660-millimeter) torpedo tubes. Seawolf was fast (top speed of over 60 kilometers an hour) and much quieter than the Los Angeles boats. To replace the un-built Seawolfs the Virginia-class was designed. Think of it as a Los Angeles size hull with a lot of Seawolf technology installed. The Virginia class boats ended up costing about half as much as the Seawolfs. But that was largely possible because the Virginias used a lot of the new technology developed for Seawolf. --- Timothy W. Coleman